1. Field of the Invention
The present invention relates to a coupled torsion beam axle (CTBA) which is a kind of suspension of a vehicle, and more particularly, to a CTBA having a swing joint, which changes the geometric characteristic of the CTBA using a swing joint, thereby improving stability during steering or braking.
2. Description of Related Art
A CTBA which is usually mounted as a suspension in a small vehicle has a simpler structure and a smaller number of parts than other suspensions, and may be manufactured at a smaller weight than other suspensions.
FIGS. 1 and 2 schematically illustrate the structure of a CTBA according to the related art. As illustrated in FIGS. 1 and 2, the CTBA includes a torsion beam 111 provided in the widthwise direction of a vehicle, a trailing arm 112 provided at both ends of torsion beam 111, and a wheel mount bracket 114 having a rear wheel RW mounted at an end of trailing arm 112.
The CTBA according to the related art has a structural characteristic that the rear wheel is toed out during steering or braking, thereby reducing steering stability or braking stability.
As illustrated in FIG. 1, when the vehicle is steered toward the right side of FIG. 1 as indicated by an arrow, the left and right rear wheels are steered toward the right side, and particularly, the outer rear wheel is less steered than the traveling direction of the vehicle. Therefore, the rear wheel is toed out.
During braking as illustrated in FIG. 2, the car body tends to continuously advance due to the influence of inertia, compared with the rear wheels braked by a braking force. Therefore, the torsion beam is minutely deformed in a convex shape toward the traveling direction of the vehicle. Accordingly, the rear wheels are opened toward outside and toed out, which may hurt the braking stability.
Meanwhile, in order to prevent the toe out of the rear wheels which inevitably occurs in the CTBA, a variety of methods have been proposed.
For example, Korean Patent Application Laid-Open No. 10-2006-0006797 has disclosed technology for controlling the toe values of rear wheels. In the technology, an actuator and a link member capable of adjusting the tow values of the rear wheels are provided in a CTBA, and a controller operates the actuator according to a traveling condition and controls the toe values of the rear wheels.
However, the technology for adjusting the toe values of the rear wheels through electronic control requires a high cost. Therefore, the production cost of the vehicle increases, and the construction thereof becomes complex.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.